Conventional metal sandwich panels having metal sheets of equal thickness on both sides are well known in the art, and the market is presently evenly divided between cold storage and industrial/architectural uses. Approximately 36 million square feet of usage is in wall panels, with only an estimated 4 million square feet in roofing. Growth in the roofing segment has been more limited due to concerns surrounding through-fastened assemblies, although standing seam metal roofing is gaining wider acceptance.
From a product performance standpoint, metal sandwich panels offer the highest value in use for cold storage construction. Their insulating efficiency is unmatched. More importantly, metal skins provide an optimum vapor barrier, particularly when combined with closed cell polyurethane or polyisocyanurate foams. Properly assembled, these systems prevent either moisture intrusion or interior condensation. Not surprisingly, metal sandwich panels are preferred in high humidity process environments, such as those in the paper industry.
Despite performance advantages, metal sandwich panels have remained a relatively high cost product with limited use despite tremendous growth for metal buildings in general. With typical metal sandwich panel costs ranging from $2.50 to $5.00 per square foot, these products have remained uncompetitive with conventional fiberglass insulated metal panel systems. A significant improvement in product design and economics is desired to improve demand for metal sandwich panels.